1. Field of the Invention
The present invention relates to an organic light emitting display and a method of driving the same.
2. Description of Related Art
In recent years, various flat panel displays have been developed having reduced weight and volume in comparison to the cathode ray tube display. These flat panel displays include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display, etc.
Amongst the various flat panel displays, the organic light emitting display displays an image by using organic light emitting diodes which generate light by the recombination of electrons and holes. The organic light emitting display has a rapid response time and a low power consumption.
However, a reference power (Vref) supplied to a data driver and a first power (ELVDD) generated in a power source unit are supplied by separate power sources in conventional organic light emitting displays. When the reference power (Vref) and the first power (ELVDD) are provided by separate power sources, it is difficult to charge a desired voltage in a storage capacitor (Cst) due to voltage ripples.
More particularly, a first power (ELVDD) generated in the power source unit and a data signal generated by the reference power (Vref) show a ripple in which a voltage repeatedly increases and decreases. Therefore, a power may be charged in the storage capacitor (Cst) at a point of time when the voltage of the data signal increases, and the voltage of the first power (ELVDD) decreases in certain pixels. Also, a power may be charged in the storage capacitor (Cst) at a point of time when the voltage of the data signal decreases, and the voltage of the first power (ELVDD) increases in the other pixels. Therefore, although the same data signal is supplied to the pixels, lights generated by the pixels may have different luminance.
Also, when the first power (ELVDD) or the reference power (Vref) experiences noises from the outside environment, it is difficult to display a desired image since the noises directly affect the luminance of the displayed image.